<div class="header">
  <a [routerLink]="[ '/home']" routerLinkActive="active">首页</a>
  <a [routerLink]="[ '/product']" routerLinkActive="active">商品</a>
  <a [routerLink]="[ '/news']" routerLinkActive="active">新闻</a>
</div>

<router-outlet></router-outlet>
